This invention relates to fire retardant compositions and their use on combustible substrates to impart fire retardancy thereto. More particularly, the invention relates to the use of fire retardant compositions on combustible foamed and fibrous substrates wherein the resiliency of the substrate is retained after application of the composition.
Prior compositions intended for flame or fire proofing foamed or fibrous materials either reduced the compressibility and rebound of the materials or were water or solvent soluble and therefore only a temporary treatment. The compositions of the present invention are designed to impart fire retardancy to such substrates without affecting the resiliency or normal compressibility and rebound of the treated substrate while being inert to water and other solvents.
U.S. Pat. Nos. 4,018,983, 4,064,359 and 4,225,649 disclose fire retardant compositions which incorporate fibrous materials as a functional part of the compositions; while utilizing some components in common with the present formulations, they do so in differing amounts. The compositions of these patents are designed as coatings for electrical cables. U.S. Pat. No. 4,162,342 discloses a process for making foam as an end product, in distinction with the present invention which provides a composition to be applied to previously manufactured foamed substrates. U.S. Pat. No. 3,914,513 discloses the use of chlorinated paraffin wax as a material used in flame retardant compositions. U.S. Pat. Nos. 3,940,549 and 4,027,062 disclose antimony oxide as being useful in flame retardant compositions.
U.S. Pat. No. 4,493,871 discloses the use of chlorinated paraffin wax as a material used in flame retardant compositions as a plasticizer, in distinction with the present invention which uses the material to suppress afterglow, any plasticizing effect being deleterious to the composition. Also mentioned in U.S. Pat. No. 4,493,781 are vinylidine chloride copolymers having higher vinylidine chloride content and a corresponding bound chlorine content than used in the present invention. The use of various metal oxides, in particular antimony pentoxide, is also mentioned but at a higher level than is useful in the present invention.